Conventionally, as shown in FIG. 4, a carburetor unit 1, which is formed by aluminum die cast molding or the like, has a fuel supply path formed inside and a solenoid valve 2 inserted into an opening 12 formed in a surface 11 thereof and which communicates with the fuel supply path.
The solenoid valve 2 typically includes a hard synthetic resin cover 22 placed there over in which a connector 21 is formed as a protrusion for supplying power to a built-in solenoid and an exposed tip (insertion portion) 23 which is inserted into the opening 12. However, if inserted this way it will come out. Therefore, as shown in FIG. 5, for example, the solenoid valve 2 has been attached to the carburetor unit 1 by securing a flange portion 24 formed on the cover 2 with a bolt 13 that is screwed into the carburetor unit 1 through a bolt hole (not shown in the drawings) provided near the opening 12 in the surface 11 of the carburetor unit 1.
However, with the conventional attachment structure of the solenoid valve 2 as shown in FIG. 4, the bolt 13 is attached in an eccentric position, making it difficult to secure the solenoid valve 2 in a stable condition.
One known example of an attachment structure using attachment securing implements is presented in JP 2005-163816 A.
This attachment structure for a solenoid valve 2, as shown in FIG. 6, for example, involves attachment to the surface 11 of the carburetor unit 1 by means of an attachment screw 31 using an attachment securing implement 3 formed from metal, for example. With this attachment structure, the number of parts increases, as the attachment securing implement 3 is needed, and a bolt is also needed for the securing.
This has resulted in problems in manufacturing, since the attachment work is troublesome and the tightness of the bolt 13 has to be checked, too. The bolt 13 can come loose due to vibration over many years of use, and it is also a hassle to remove them for repair or exchange, which is a problem.